[spring] Updating the SPRING WG Charter

[Rob Shakir <[e-mail]>]

Hi SPRING,

After the discussions on the list and in London relating to the charter,
Bruno and I have been working to propose a new charter for the WG with
Martin, and the other routing ADs. The text for this suggested charter is
below. We would like to solicit WG feedback on the charter text prior to
Martin taking to the IESG. We'd like to try and get the charter agreed
prior to IETF 102 in Montréal.

The Source Packet Routing in NetworkinG (SPRING) Working Group is the home
of
Segment Routing (SR) using MPLS (SR-MPLS) and IPv6 (SRv6). SPRING WG serves
as
a forum to discuss SPRING networks operations, define new applications, and
specify extensions of Segment Routing technologies.

The SPRING WG defines procedures that allow a node to steer a packet
through an
SR Policy instantiated as an ordered list of instructions called segments
and
without the need for per-path state information to be held at transit nodes.
Full explicit control (through loose or strict path specification) can be
achieved in a network comprising only SPRING nodes, however SPRING nodes
must
inter-operate through loose routing in existing networks and may find it
advantageous to use loose routing for other network applications.

The scope of the SPRING WG work includes both single Autonomous System (AS)
and
multi-AS environments. Segment Routing operates within a trusted domain; as
described in the architecture, a node imposing a segment list is assumed to
be
allowed to do so. Nonetheless, the SPRING WG must strive to identify and
address security considerations brought up by the technologies it defines.
The
technologies SPRING WG defines may be applicable to both centralised and
distributed path computation.

SPRING WG should avoid modification to existing data planes that would make
them incompatible with existing deployments. Where possible, existing
control
and management plane protocols must be used within existing architectures to
implement the SPRING function. Any modification of - or extension to -
existing
architectures, data planes, or control or management plane protocols should
be
carried out in the WGs responsible for the architecture, data plane, or
control
or management plane protocol being modified and in coordination with the
SPRING
WG, but may be done in SPRING WG after agreement with all the relevant WG
chairs and responsible Area Directors.


The SPRING WG will manage its specific work items by milestones agreed with
the
responsible Area Director.

The work-items of the SPRING WG include functional specifications for:

o Segment Routing policies and the associated steering and traffic
engineering
  mechanisms.

o Source-routed stateless service chaining using SR-MPLS and SRv6
dataplanes.

o SRv6 network programming for the underlay networks and overlay services,
and
  including data plane behavior and functions associated with SIDs

o Operation, Administration and Management (OAM), and traffic accounting in
  networks with SR-MPLS and SRv6 data planes in the case where SR introduces
  specificities compared to MPLS or IPv6 technologies.

o Performance Management (PM) and monitoring in networks with SR-MPLS and
SRv6
  data planes in the case where SR introduces specificities compared to
MPLS or
  IPv6 technologies.

o The inter-working between SRv6 and SR-MPLS.

o Using SR as the mechanism to identify sets of resources in networks with
  SR-MPLS and SRv6 dataplanes.

Any of the above may require architectural extensions.

The work-items of SPRING WG also include:

o Specification of management models (YANG) for Segment Routing
applications,
  services and networks with SR-MPLS and SRv6 dataplanes.

The SPRING WG will coordinate and collaborate with other WGs as needed.
Specific
expected interactions include (but may not be limited to):

* mpls on the MPLS dataplane and OAM extensions,
* 6man on the IPv6 dataplane for SR and associated OAM extensions
* lsr on OSPF and IS-IS extensions to flood SPRING-related information
        * idr for BGP extensions
* bess for VPN control plane
* pce on extensions to communicate with an external entity to compute and
program SPRING paths
* teas on generic traffic engineering architecture

Please comment on the contents of the charter text on the list.

Thanks,
Bruno & Rob